1. Field of the Invention
The present invention relates to a zoom lens and an imaging apparatus, and more particularly to a zoom lens that can be used for an electronic camera such as a digital camera, a video camera, a broadcasting camera, a movie camera, a surveillance camera, and the like as well as an imaging apparatus mounted with this zoom lens.
2. Description of the Related Art
Conventionally, zoom lenses, which consist of a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive or negative refractive power, a fourth lens group having a positive refractive power, and a fifth lens group having a positive or negative refractive power in this order from the object side, in which the first, third, and fifth lens groups are fixed while the second and fourth lens groups are configured to move when changing magnification, are known as zoom lenses to be mounted onto a TV camera in the field described above.
In zoom lenses having such a configuration, lens groups which move for focusing can be reduced in size and weight, AF (autofocus) is easily attained, and a configuration, in which the total length is fixed, is possible even in the case that the magnification ratio is set to be greater. For example, the zoom lenses disclosed in Patent Documents 1 and 2 (Japanese Unexamined Patent Publication No. 2007-010903 and Japanese Unexamined Patent Publication No. 2013-037063) are known as this type of zoom lens.